An Investigation of the Growth Inhibitory Capacity of Several Medicinal Plants From Iran on Tumor Cell Lines

Abstract

Background: Traditional herbal medicine is a valuable resource that provides new drugs for cancer treatment.

Objectives: In this study we aim to screen and investigate the in vitro anti-tumor activities of ten species of plants commonly grown in Southern Iran.

Materials and methods: We used the MTT colorimetric assay to evaluate the cytotoxic activities of the methanol extracts of these plants on various tumor cell lines. The IC50 was calculated as a scale for this evaluation.

Results: Satureja bachtiarica, Satureja hortensis, Thymus vulgaris, Thymus daenensis and Mentha lonigfolia showed the inhibitoriest effects on Jurkat cells with > 80% inhibition at 200 µg/mL. Satureja hortensis (IC50: 66.7 µg/mL) was the most effective. These plants also strongly inhibited K562 cell growth; Satureja bachtiarica (IC50: 28.3 µg/mL), Satureja hortensis (IC50: 52 µg/mL) and Thymus vulgaris (IC50: 87 µg/mL) were the most effective extracts. Cichorium intybus, Rheum ribes, Alhagi pseudalhagi and Glycyrrihza glabra also showed notable effects on the leukemia cell lines. The Raji cell line was mostly inhibited by Satureja bachtiarica and Thymus vulgaris with approximately 40% inhibition at 200µg/ml. The influence of these extracts on solid tumor cell lines was not strong. Fen cells were mostly affected by Glycyrrihza glabra (IC50: 182 µg/mL) and HeLa cells by Satureja hortensis (31.6% growth inhibitory effect at 200 µg/mL).

Conclusions: Leukemic cell lines were more sensitive to the extracts than the solid tumor cell lines; Satureja hortensis, Satureja bachtiarica, Thymus vulgaris, Thymus daenensis and Mentha lonigfolia showed remarkable inhibitory potential.

Keywords: Cytotoxicity; Medicinal Plants; Tumor Cell Lines.

Figure 1.. Effects of the Methanolic Extract of Various Medicinal Plants on Different Cell Lines Determined by MTT Colorimetric Assay

Cells were treated with various concentrations of the extracts for 48 hours. Negative control was cells treated only with solvent (DMSO) at concentrations equal to test wells. Percentage inhibition was calculated according to the formula in the text. Values represent the mean ± standard deviation from three sets of independent experiments.

Figure 2.. IC50 Values for the Effects of the Methanolic Extract of Various Medicinal Plants on Jurkat and K562 Cell Lines After 48 Hours of Exposure Determined by MTT Colorimetric Assay

Negative control was cells treated only with solvent (DMSO) at concentrations equal to test wells. Percentage inhibition from three sets of independent experiments was determined and then IC50 values were calculated by using curve expert software. IC50 values of plants 1, 3, 5 and 6 on Jurkat cells and plants 1 and 2 on K562 cells are 400 µg/mL or greater.